A Lithium-Ion Battery of German manufacturer Akasol is pictured past an electronic car during a media preview day at the Frankfurt Motor Show (IAA) September 11, 2013. The world's biggest auto show is... more&nbsp

A Lithium-Ion Battery of German manufacturer Akasol is pictured past an electronic car during a media preview day at the Frankfurt Motor Show (IAA) September 11, 2013. The world's biggest auto show is open to the public September 14 -22. REUTERS/Ralph Orlowski (GERMANY - Tags: BUSINESS TRANSPORT) less&nbsp